Under Win 7 I created a new 100 GB disk partition (L:) to install Ubuntu 12.04. I then rebooted from the Ubuntu install CD, selected "Install side by side" and now I'm stuck. I end up at the Advanced Partitioning Tool and I do not know how to tell the installer to use the L: partition. Any help would be appreciated. Thanks!

Thank you. I have successfully installed Ubuntu 12.04 alongside Win 7. However, now when I reboot the laptop it goes directly to Win 7 with no option to choose Ubuntu. Any thoughts on how to get the boot-time choice to show up? Thanks!

  • 1
    This may be due to GRUB being installed in the Live USB (if you used an USB drive for installation), instead of being in the /dev/sda. Please search for answers to similar questions and ask a new question if needed. If you found any of the answers below to be the right answer, please accept it with a green tick mark so that others can benefit from it.
    – user68186
    Sep 17, 2012 at 20:31
  • Does this answer your question? Can't boot into Ubuntu in Windows 10 / Ubuntu dual boot
    – karel
    Feb 2, 2020 at 15:04

4 Answers 4


Choose the something else option while installing.

You can identify the L: partition by looking the sizes of the partitions.... Once you find it, click on change and choose the ext4 file system and / (root)

Ubuntu will format it with ext4 and will get installed there.... You also will have to decide the swap partition(which is optional) according to your RAM size

I did the same :)

Hope that helps...



For your second question, you need to repair your grub so that it will show boot menu on system start up.
Please visit https://help.ubuntu.com/community/RecoveringUbuntuAfterInstallingWindows

  1. Boot into live session
  2. Install boot repair tool as mentioned in above link and follow the instruction

Good Luck!


I used to dual boot. But when one OS had a problem, the only way to fix it was reinstalling BOTH operating systems. I also had problems dual booting with Fedora. Now I use VirtualBox and run virtual instances of operating systems instead. If one of the virtual OS's dies, I just delete it and create a new one.


Update for Ubuntu 18.04 and above

New installations of recent versions of Ubuntu does not use a separate swap partition any more. They use a swap file by default.

Original Answer

Boot windows and delete the 100GB partition (L:) and try again. Ubuntu needs to create at least two partitions, "/" in ext4 format and "swap" in it's own format in place of (L:) during installation. It will find the unused space and do what is needed.

You can also choose "Something else" during installation and manually create these partitions. The swap partition is needed for virtual memory management and can be 2GB-4GB in size.

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